#ifndef _ARRAY_SENTINEL_H_
#define _ARRAY_SENTINEL_H_

#include <stdlib.h>

#define SET__SIZE 256

struct set {
  char s[SET__SIZE];
  int size;
};


struct set*  set__empty(struct set *);
size_t   set__size(const struct set *);

int    set__is_empty(const struct set *);
int    set__find(const struct set *, char);
struct set* set__inter(const struct set * s1, const struct set * s2, struct set * si);
struct set* set__union(const struct set * s1, const struct set * s2, struct set * su);
struct set* set__add(struct set *, char);
struct set* set__remove(struct set *, char);
void set__display(struct set* s);
int compare (struct set * s1 , struct set * s2);
struct set* set__copy (struct set * o, struct set * d);


#endif
